﻿function Generate_Brief(text, length) {
    if (text.length < length) return text;
    var Foremost = text.substr(0, length);
    var re = /<(\/?)(BODY|SCRIPT|P|DIV|H1|H2|H3|H4|H5|H6|ADDRESS|PRE|TABLE|TR|TD|TH|INPUT|SELECT|TEXTAREA|OBJECT|A|UL|OL|LI|BASE|META|LINK|HR|BR|PARAM|IMG|AREA|INPUT|SPAN)[^>]*(>?)/ig;
    var Singlable = /BASE|META|LINK|HR|BR|PARAM|IMG|AREA|INPUT/i
    var Stack = new Array(), posStack = new Array();
    while (true) {
        var newone = re.exec(Foremost);
        if (newone == null) break;
        if (newone[1] == "") {
            var Elem = newone[2];
            if (Elem.match(Singlable) && newone[3] != "") {
                continue;
            }
            Stack.push(newone[2].toUpperCase());
            posStack.push(newone.index);
            if (newone[3] == "") break;
        } else {
            var StackTop = Stack[Stack.length - 1];
            var End = newone[2].toUpperCase();
            if (StackTop == End) {
                Stack.pop();
                posStack.pop();
                if (newone[3] == "") {
                    Foremost = Foremost + ">";
                }
            }
        };
    }
    var cutpos = posStack.shift();
    Foremost = Foremost.substring(0, cutpos);
    return Foremost;
}